Oil pan drain plug and wrench therefor



Nov. 21, 1967 A- B. HERR OIL PAN DRAIN PLUG AND WRENCH THEREFOR Filed Aug. 10, 1966 United States Patent 3,353,428 OIL PAN DRAIN PLUG AND WRENCH THEREFOR Alfred B. Herr, West Chester, Pa., assignor of onetwentieth to John L. Johnson, Toronto, Ontario, Canada Filed Aug. 10, 1966, Ser. No. 571,568 Claims. CI. 81-71) ABSTRACT OF THE DISCLOSURE This invention provides a drain plug for the oil pan of motor vehicles, which may be removed from beneath the vehicle, in the conventional manner, or from above, the drain plug having a socket in the upper end thereof to receive a wrench, the wrench passing into the drain pan in the manner of an oil guage stick, and being constructed so as to be utilized as an oil guage stick.

This invention relates to the drain plug of oil pans in motor vehicles. More particularly, the invention provides an oil pan drain plug and a wrench therefor whereby the drain plug is accessible from above the motor so that the old oil may be drained with considerable ease and less messiness than normally attends this unpleasant task.

Hitherto, recourse has been had to a threadably secured plug in the base wall of oil pans which is entirely removed, usually while the vehicle is elevated, when it is desired to drain the old oil. Where means for elevating the vehicle, such as the hydraulically actuated lifts in service stations, are not readily available, it is necessary that a person place himself under the vehicle to accomplish the desired task. Not only is this recognizably an unpleasant task, in view of the dirt and the like involved and the contortions necessary to assume the required position, but an inherent danger is present when conventional jacks are utilized to partially raise the vehicle.

The present invention provides a plug in the base wall of the oil pan which extends inwardly thereof, a socket is provided in the upper end of the plug to accommodate a wrench, the wrench passing into the oil pan from above, preferably through the passage provided for the oil guage stick; the lower portion of the plug being provided with threads cooperable with threads in the base wall of the oil pan; at least one opening through the wall of the plug and longitudinally thereof whereby, upon the plug being rotated to expose a portion of the opening below the base wall, the oil is drained. Further, the said opening will maintain the oil level within the plug equal to the level in the oil pan so that the oil level may be read on an oil guage stick, or an extension on the wrench providing an oil guage stick, passing within the plug.

In the following detailed description, reference will be had to the accompanying drawings wherein like characters of reference refer to like parts in the several views and in which:

FIG. 1 is an elevational view of the invention in rela tion to the oil pan and engine block of a motor vehicle, the oil pan and engine block being broken away to disclose the said view;

FIG. 2 is an enlarged, vertical mid-sectional view of the drain plug of the invention;

FIG. 3 is a sectional view, again enlarged, taken on the line 3-3 of FIG. 2;

FIG. 4 is a front, elevational view of the wrench c0- operable with the drain plug of this invention.

Referring to the drawings, the oil pan 11 is secured subjacent the engine block 12 of the motor vehicle to which the invention relates. A plurality of nut and bolt assem- "ice blies or other conventional means secure the oil pan 11 thereat in the normal manner at the flange 12a of the block 12 and the flange 11a of the oil pan 11. The tubular member 14 secured to the block 12, adjacent the flange 12a, and in axial alignment with the passage 15 through the marginal portion of the block 12.

The plug 16 is located in the base wall 17 of the pan 11 adjacent the side wall 18. An off-set portion 19 of the base wall 17 is provided, the off-set portion 19 threadably retaining the plug 16 in axial alignment with the passage 15 and facilitating the complete drainage of the pan 11. Preferably, the off-set portion 19 is of a greater thickness than the walls of the oil pan 11.

The plug 16 includes a head portion 20 at the base end thereof. The head portion 20 may take the form of a hexagon or square in section so as to be cooperable with a conventional wrench so that the oil pan 11 may be drained in the conventional manner.

A tubular stem 21 is perpendicular to the head portion 20, the lower portion 22 of the stem 21 being provided with an external thread cooperable with an internal thread in the off-set portion 19 whereby the plug 16 travels in an axial direction upon rotation thereof. A pair of vertically opposite openings 23, longitudinally of the plug 16, are provided in the threaded portion 22 of the stem 21, the lower end of the openings 23 terminating in spaced apart relation to the head portion 20 to assure a sealing action thereat when the plug 16 is in the closed position.

The'upper end 24 of the stem 21 is provided with a socket 25 having a square configuration in section so as to accommodate therein the configuration 27 provided on the wrench 26.

The wrench 26 passes through the tubular member 14 and the passage 15 so as to engage with the plug 16 in axial alignment. The portion 27 of the wrench 26 is accommodated within the socket 25 whereby the plug 16 may be rotated to expose a portion of the openings 23 subjacent the off-set portion 19 to drain the oil from the pan 11. The bead 28 is provided about the plug 16 to restrict the longitudinal movement thereof, the bead 28 being adjacent the upper end of the threaded portion 22.

The extension 29 of the wrench 26 includes indented graduations therealong to provide a guage whereby a reading of the amount of oil within the pan 11 may be obtained. The handle 31 is provided for manipulation of the wrench 26 to rotate the plug 16.

It may be seen that the openings 23 in the plug 16 permits drainage of the pan 11 upon the plug 16 being rotated to the open position. Further, the openings 23 permits the level of the oil within the hollow body of the plug 16 to be indicative of the oil level in the oil pan 11 when read on the graduations 30 of the extension 29 or an oil guage stick.

It may now be seen that the invention achieves the intended objects. When it is desired to drain the oil from the oil pan 11, the Wrench 26 is engaged with the plug 16 and is rotated so that the plug 16 is caused to travel axially downwardly to the open position, permitting the oil to flow through the openings 23. When the oil pan 11 has been drained the wrench 26 and the plug 16 are rotated in the reverse direction so that the plug 16 is caused to travel axially upward to the closed position, at which position the head portion 20 abuts the off-set portion 19. Because the openings 23 are spaced apart from the head portion 20, a sealing action is assured.

Further, in view of the periodic oil changes recommended by the manufacturers for proper maintenance of motor vehicles, considerable savings may be realized by the individual vehicle owner who may change the oil himself with relative ease when utilizing the described invention, and is therefore more likely to follow the manufacturers recommendation. In service stations, the attendant may change the oil of a number of vehicles simultaneously and with ease, while the hydraulic lift is made available for other purposes.

The oil drain plug and wrench of this invention may be incorporated in motor vehicles on the assembly line with a relatively low capital expenditure, whereby a very low cost per installation may be achieved. Further, conventional oil pans may be readily replaced with oil pans incorporating the described invention at a moderate cost.

As many changes could be made in the described construction without departing from the scope of the invention as defined in the following claims, it is intended that all matter contained in the above description, or shown in the accompanying drawings, shall be interpreted as illustrative only and not in a limiting sense.

What is claimed is:

1. An oil pan drain plug and wrench therefor, said plug being threadably retained in the base Wall of said oil pan and extending inwardly thereof, means in the upper end of said plug to cooperate with said wrench, said wrench extending downwardly and engaging said means in the upper end of said plug, at least one opening in the Wall of said plug whereby upon the said plug being rotated to expose a'portion of said opening below the said wall of the oil pan the oil therein will be drained.

2. An oil pan drain plug and Wrench therefor as defined in claim 1 in which said wrench passes through the passage into the oil pan provided for the oil guage stick to engage with said means in the uppper end of said plug.

3. An oil pan drain plug and Wrench therefor as defined in claim 2 including an extension on said wrench and graduations on said extension whereby said wrench may be utilized as an oil gauge stick.

4. An oil pan drain plug and wrench therefor as defined in claim 1 in which said plug includes a head portion at the base end thereof, said head portion being cooperable with a conventional wrench whereby the oil pan may be drained in the conventional manner; a tubular stem perpendicular to said head portion, the lower portion of said sternbeing provided with an external thread cooperable with an internal thread in said base wall, said opening being longitudinal of said plug and in said threaded portion, the lower end of said opening terminating in spaced apart relation to said head portion; said means being a socket in the upper end of said stem, said socket accommodating a cooperating portion of said wrench; a bead about said stem adjacent to the said threaded portion, said bead restricting longitudinal movement of said plug; said wrench engaging with said socket in substantially axial alignment with said plug, and a handle means on said wrench whereby said wrench may be manipulated to rotate said plug.

5. An oil pan drain plug and wrench therefor as defined in claim 4 in which said wrench includes an extension, said extension having graduations indented therealong whereby a reading of the amount of oil within the oil pan may be obtained.

References Cited UNITED STATES PATENTS 1,389,997 9/1921 Sedgwick 81-71 2,577,590 12/1951 Payne a 73290 FOREIGN PATENTS 150,702 11/1921 Great Britain.

JAMES L. JONES, JR., Primary Examiner. 

1. AN OIL PAN DRAIN PLUG AND WRENCH THEREFOR, SAID PLUG BEING THREADABLY RETAINED IN THE BASE WALL OF SAID OIL PAN AND EXTENDING INWARDLY THEREOF, MEANS IN THE UPPER END OF SAID PLUG TO COOPERATE WITH SAID WRENCH, SAID WRENCH EXTENDING DOWNWARDLY AND ENGAGING SAID MEANS IN THE UPPER END OF SAID PLUG, AT LEAST ONE OPENING IN THE 